How to use

expression

method

in

org.sonar.plugins.java.api.tree.ExpressionStatementTree

@CheckForNull
private static ExpressionTree expressionFromSingleStatementBlock(List<StatementTree> body) {
 if (body.size() == 1) {
  StatementTree singleStatement = body.get(0);
  if (singleStatement.is(Tree.Kind.EXPRESSION_STATEMENT)) {
   return ((ExpressionStatementTree) singleStatement).expression();
  }
 }
 return null;
}

@Override
public void visitExpressionStatement(ExpressionStatementTree tree) {
 scanSkippingIncrementOrDecrement(tree.expression());
}

private static boolean hasOneAssignementStatement(MethodTree methodTree, ClassTree classTree) {
 List<StatementTree> body = methodTree.block().body();
 return body.size() == 1 && body.get(0).is(Tree.Kind.EXPRESSION_STATEMENT) && ((ExpressionStatementTree) body.get(0)).expression().is(Tree.Kind.ASSIGNMENT)
   && referencePrivateProperty((AssignmentExpressionTree) ((ExpressionStatementTree) body.get(0)).expression(), classTree);
}

private static boolean hasOneAssignementStatement(MethodTree methodTree, ClassTree classTree) {
 List<StatementTree> body = methodTree.block().body();
 return body.size() == 1 && body.get(0).is(Tree.Kind.EXPRESSION_STATEMENT) && ((ExpressionStatementTree) body.get(0)).expression().is(Tree.Kind.ASSIGNMENT)
   && referencePrivateProperty((AssignmentExpressionTree) ((ExpressionStatementTree) body.get(0)).expression(), classTree);
}

private boolean hasOneAssignementStatement(MethodTree methodTree, ClassTree classTree) {
 List<StatementTree> body = methodTree.block().body();
 return body.size() == 1 && body.get(0).is(Tree.Kind.EXPRESSION_STATEMENT) && ((ExpressionStatementTree) body.get(0)).expression().is(Tree.Kind.ASSIGNMENT)
   && referencePrivateProperty((AssignmentExpressionTree) ((ExpressionStatementTree) body.get(0)).expression(), classTree);
}

private static boolean isLastStatement(@Nullable BlockTree blockTree, MethodInvocationTree lastStatementTree) {
 if (blockTree != null) {
  StatementTree last = Iterables.getLast(blockTree.body());
  if (last.is(Kind.EXPRESSION_STATEMENT)) {
   return lastStatementTree.equals(((ExpressionStatementTree) last).expression());
  } else if (last.is(Kind.TRY_STATEMENT)) {
   return isLastStatement(((TryStatementTree) last).finallyBlock(), lastStatementTree);
  }
 }
 return false;
}

private static boolean isLastStatement(@Nullable BlockTree blockTree, MethodInvocationTree lastStatementTree) {
 if (blockTree != null) {
  StatementTree last = Iterables.getLast(blockTree.body());
  if (last.is(Kind.EXPRESSION_STATEMENT)) {
   return lastStatementTree.equals(((ExpressionStatementTree) last).expression());
  } else if (last.is(Kind.TRY_STATEMENT)) {
   return isLastStatement(((TryStatementTree) last).finallyBlock(), lastStatementTree);
  }
 }
 return false;
}

@Override
public void visitExpressionStatement(ExpressionStatementTree tree) {
 ExpressionTree expressionTree = ExpressionUtils.skipParentheses(tree.expression());
 expressionTree = skipChainedAssignments(expressionTree);
 scan(expressionTree);
}

@Override
public void visitNode(Tree tree) {
 ExpressionStatementTree est = (ExpressionStatementTree) tree;
 if (est.expression().is(Tree.Kind.METHOD_INVOCATION)) {
  MethodInvocationTree mit = (MethodInvocationTree) est.expression();
  Type methodType = mit.symbolType();
  if (!returnsVoid(methodType) && isCheckedType(mit)) {
   addIssue(tree, "The return value of \"" + methodName(mit) + "\" must be used.");
  }
 }
}

@Override
public void visitExpressionStatement(ExpressionStatementTree tree) {
 super.visitExpressionStatement(tree);
 // TODO(Godin): strictly speaking statement can't have type
 registerType(tree, getType(tree.expression()));
}

@Override
public void visitExpressionStatement(ExpressionStatementTree tree) {
 ExpressionTree expressionTree = ExpressionUtils.skipParentheses(tree.expression());
 expressionTree = skipChainedAssignments(expressionTree);
 scan(expressionTree);
}

private static boolean isLoggingMethod(StatementTree statementTree, IdentifierTree exceptionIdentifier) {
 if (!statementTree.is(Tree.Kind.EXPRESSION_STATEMENT)) {
  return false;
 }
 ExpressionTree expression = ((ExpressionStatementTree) statementTree).expression();
 if (expression.is(Tree.Kind.METHOD_INVOCATION)) {
  MethodInvocationTree mit = (MethodInvocationTree) expression;
  return LOGGING_METHODS.anyMatch(mit) && isExceptionUsed(exceptionIdentifier, mit);
 }
 return false;
}

private static boolean isLoggingMethod(StatementTree statementTree, IdentifierTree exceptionIdentifier) {
 if (!statementTree.is(Tree.Kind.EXPRESSION_STATEMENT)) {
  return false;
 }
 ExpressionTree expression = ((ExpressionStatementTree) statementTree).expression();
 if (expression.is(Tree.Kind.METHOD_INVOCATION)) {
  MethodInvocationTree mit = (MethodInvocationTree) expression;
  return LOGGING_METHODS.anyMatch(mit) && isExceptionUsed(exceptionIdentifier, mit);
 }
 return false;
}

@Override
public void visitNode(Tree tree) {
 ExpressionStatementTree expressionStatement = (ExpressionStatementTree) tree;
 ExpressionTree expression = expressionStatement.expression();
 if (expression.is(Tree.Kind.NEW_CLASS)) {
  NewClassTreeImpl newClassTree = (NewClassTreeImpl) expression;
  String className = newClassTree.getConstructorIdentifier().name();
  addIssue(tree, "Either remove this useless object instantiation of class \"" + className + "\" or use it");
 }
}

private boolean isUselessSuperCall(MethodTree methodTree) {
 ExpressionTree callToSuper = null;
 StatementTree statementTree = methodTree.block().body().get(0);
 if (returnsVoid(methodTree) && statementTree.is(Tree.Kind.EXPRESSION_STATEMENT)) {
  callToSuper = ((ExpressionStatementTree) statementTree).expression();
 } else if (statementTree.is(Tree.Kind.RETURN_STATEMENT)) {
  callToSuper = ((ReturnStatementTree) statementTree).expression();
 }
 return callToSuper != null && isCallToSuper(methodTree, callToSuper);
}

private void leaveExpressionStatement(ExpressionStatementTree expressionStatement) {
 ExpressionTree expression = expressionStatement.expression();
 if (expression.is(ASSIGNMENT_KINDS)) {
  addAssignment(((AssignmentExpressionTree) expression).variable());
 } else if (expression.is(INCREMENT_KINDS)) {
  addAssignment(((UnaryExpressionTree) expression).expression());
 }
}

private void leaveExpressionStatement(ExpressionStatementTree expressionStatement) {
 ExpressionTree expression = expressionStatement.expression();
 if (expression.is(ASSIGNMENT_KINDS)) {
  addAssignment(((AssignmentExpressionTree) expression).variable());
 } else if (expression.is(INCREMENT_KINDS)) {
  addAssignment(((UnaryExpressionTree) expression).expression());
 }
}

private static boolean isUselessSuperCall(MethodTree methodTree) {
 ExpressionTree callToSuper = null;
 StatementTree statementTree = methodTree.block().body().get(0);
 if (returnsVoid(methodTree) && statementTree.is(Tree.Kind.EXPRESSION_STATEMENT)) {
  callToSuper = ((ExpressionStatementTree) statementTree).expression();
 } else if (statementTree.is(Tree.Kind.RETURN_STATEMENT)) {
  callToSuper = ((ReturnStatementTree) statementTree).expression();
 }
 return callToSuper != null && isCallToSuper(methodTree, callToSuper) && sameVisibility(methodTree.symbol(), ((MethodInvocationTree) callToSuper).symbol());
}

private static boolean isUselessSuperCall(MethodTree methodTree) {
 ExpressionTree callToSuper = null;
 StatementTree statementTree = methodTree.block().body().get(0);
 if (returnsVoid(methodTree) && statementTree.is(Tree.Kind.EXPRESSION_STATEMENT)) {
  callToSuper = ((ExpressionStatementTree) statementTree).expression();
 } else if (statementTree.is(Tree.Kind.RETURN_STATEMENT)) {
  callToSuper = ((ReturnStatementTree) statementTree).expression();
 }
 return callToSuper != null && isCallToSuper(methodTree, callToSuper) && sameVisibility(methodTree.symbol(), ((MethodInvocationTree) callToSuper).symbol());
}

@Override
public void visitExpressionStatement(ExpressionStatementTree tree) {
 super.visitExpressionStatement(tree);
 ExpressionTree expression = tree.expression();
 if (((JavaType) expression.symbolType()).isTagged(JavaType.DEFERRED) && expression.is(Tree.Kind.NEW_CLASS)) {
  JavaType parametrizedTypeWithObject = resolve.parametrizedTypeWithErasure((ParametrizedTypeJavaType) getType(((NewClassTree) expression).identifier()));
  setInferedType(parametrizedTypeWithObject, (DeferredType) expression.symbolType());
 }
}